NAME
JSON::Types - variable type utility for JSON encoding
SYNOPSIS
# Export type functions by default
use JSON;
use JSON::Types;
print encode_json({
number => number "123",
string => string 123,
bool => bool "True value",
});
# => {"number":123,"string":"123","bool":true}
# Non export interface
use JSON::Types ();
print encode_json({
number => JSON::Types::number "123",
string => JSON::Types::string 123,
bool => JSON::Types::bool "True value",
});
DESCRIPTION
The type mappings between JSON and Perl is annoying things. For example,
use JSON;
my $number = 123;
warn "[DEBUG] number:$number\n" if $ENV{DEBUG};
print encode_json([ $number ]);
Output of this code depends on whether DEBUG environment is set or not.
If set, result is "[123]". If not to set, result is "["123"]". This is
normal behaviour on Perl though, it sometimes causes unexpected JSON
results.
There is a solution about this:
print encode_json([ $number + 0 ]);
This code always outputs "[123]". But the code is a bit ugly and not
readable at all.
This module provides some functions to fix this variable types issue:
number $foo; # is always number
string $foo; # is always string
bool $foo; # is always bool
You can fix above code by using this module like this:
use JSON;
use JSON::Types;
my $number = 123;
warn "[DEBUG] number:$number\n" if $ENV{DEBUG};
print encode_json([ number $number ]);
FUNCTIONS
There is three functions and all functions is exported by default.
If you don't want this exported functions, pass empty list to use line:
use JSON::Types ();
You should specify full function name when this case, like
"JSON::Types::number $foo" or etc.
string
number
bool
BEHAVIOURS ON UNEXPECTED ARGS
string(undef), number(undef), bool(undef) returns undef
Passing undefined variable to these functions is returns undef. If you
doesn't prefer this, have to treat this like following:
number $undef_possible_value // 0
This code returns 0 if variable is undef.
number($string)
Passing not numeric variable to number function is returns 0, but a
warning will be occurred.
AUTHOR
Daisuke Murase
COPYRIGHT AND LICENSE
Copyright (c) 2012 Daisuke Murase. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included
with this module.